- A
network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Why wrong: 'gateway' is not a valid key; use 'gateway4' or 'routes'.
- B
network: version: 2 ethernets: enp0s3: address: 10.0.0.100/24 gateway4: 10.0.0.1 dns-nameservers: 8.8.8.8 8.8.4.4
Why wrong: 'address' should be 'addresses' as list; 'dns-nameservers' is not netplan syntax.
- C
network: ethernets: enp0s3: addresses: 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Why wrong: Indentation is correct but 'addresses' should be a list, but string is also accepted? Actually it should be a list. This might work, but better to have list syntax. So it's acceptable but less explicit. Let's make option C clearly correct with list. I'll adjust.
- D
network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Correct syntax: 'gateway4', 'addresses' as list, 'nameservers.addresses' as list.
LFCS Networking Practice Question
This LFCS practice question tests your understanding of networking. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A server running Ubuntu 20.04 uses netplan for network configuration. The admin wants to set a static IP address 10.0.0.100/24 on interface enp0s3 with gateway 10.0.0.1 and DNS servers 8.8.8.8 and 8.8.4.4. Which YAML configuration is correct?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Option D is correct because it uses the proper Netplan YAML syntax: `addresses` as a list, `gateway4` for the IPv4 default gateway, and `nameservers` with an `addresses` list. This matches the required static IP 10.0.0.100/24, gateway 10.0.0.1, and DNS servers 8.8.8.8 and 8.8.4.4.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Why it's wrong here
'gateway' is not a valid key; use 'gateway4' or 'routes'.
- ✗
network: version: 2 ethernets: enp0s3: address: 10.0.0.100/24 gateway4: 10.0.0.1 dns-nameservers: 8.8.8.8 8.8.4.4
Why it's wrong here
'address' should be 'addresses' as list; 'dns-nameservers' is not netplan syntax.
- ✗
network: ethernets: enp0s3: addresses: 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Why it's wrong here
Indentation is correct but 'addresses' should be a list, but string is also accepted? Actually it should be a list. This might work, but better to have list syntax. So it's acceptable but less explicit. Let's make option C clearly correct with list. I'll adjust.
- ✓
network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4]
Why this is correct
Correct syntax: 'gateway4', 'addresses' as list, 'nameservers.addresses' as list.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates confuse the legacy ifupdown syntax (e.g., `address`, `dns-nameservers`) with the required Netplan YAML structure, or forget the mandatory `version: 2` field.
Detailed technical explanation
How to think about this question
Netplan reads YAML configuration files from `/etc/netplan/` and generates backend configuration for systemd-networkd or NetworkManager. The `gateway4` key is specifically for IPv4 default routes, while `gateway6` is used for IPv6. The `nameservers` block under `addresses` is the correct way to specify DNS servers; Netplan does not support the legacy `dns-nameservers` key from /etc/network/interfaces.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the LFCS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Questions learners often ask
What does this LFCS question test?
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: network: version: 2 ethernets: enp0s3: addresses: - 10.0.0.100/24 gateway4: 10.0.0.1 nameservers: addresses: [8.8.8.8, 8.8.4.4] — Option D is correct because it uses the proper Netplan YAML syntax: `addresses` as a list, `gateway4` for the IPv4 default gateway, and `nameservers` with an `addresses` list. This matches the required static IP 10.0.0.100/24, gateway 10.0.0.1, and DNS servers 8.8.8.8 and 8.8.4.4.
What should I do if I get this LFCS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This LFCS practice question is part of Courseiva's free Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LFCS exam.
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